I'm not overly sold on the ways, they're pretty expensive for what you get. With your lack of skills, I'd rather spend that karma on rounding out your skills to be honest. I'd grab some assensing to go with your astral perception and pick up a ranged combat skill as a backup for when drain stacks up
Well the +1 to Conjuring, at my current level, essentially equals +24 Karma right there. (I like 12d+ pools)
Totally get what your saying about a back up weapon. But, since no one in the group really plans on doing anything with Magic for Chicago given the Background count, the entire rest of the team should be MORE than "Shooty" enough. There is much talk of Samurai & Riggers galore.
Otherwise, yes, a back up is a MUST have, this to me is the one exception. I would plan on getting Assensing after the first mission along with other key skills.